|Activists entering red zone|
An estimated 50,000 protesters, led by an opposition politician and a Canada-based cleric, had been holding demonstrations in Islamabad for five days to demand the resignation of the government led by prime minister Nawaz Sharif.
But until Tuesday they had held back on threats to move on Islamabad's "red zone" which houses parliament, the prime minister's office and most foreign embassies.
Such a move risked sparking a violent confrontation with police and the army, which in an unusual move had in recent weeks been called in to buttress security in the capital, with about 700 personnel posted inside the red zone.
|Activists removing container which were kept by police|
At the risk of looking weak, Sharif opted to allow the demonstrators to move into the heart of the capital.
No attempt was made to block the progress of marchers by police, many of whom were armed with nothing more than sticks.
Protesters were even able to drive cranes into the capital to remove stacks of sea containers placed on key roads leading to the red zone.
In a tweet, his daughter Maryam Sharif said the prime minister had ordered police "not to use any kind of force against the protesters" in order to protect the many women and children among them.
Imran Khan, one of the leaders of the demonstrations, deliberately put women and children at the head of the marchers, while he was conveyed with senior party members on the roof of a specially converted sea container.
|More than 700 army personnel took control of red zone|
Khan, the leader of the Pakistan Tehreek-e-Insaf (PTI) party, is demanding the resignation of Sharif's government which he claims won a landslide victory in last year's general election on the basis of massive electoral fraud, although his allegations have not been supported by independent observers.
He has promised to turn the area in front of Pakistan's national assembly building into a "Tahrir Square", referring to the 2011 protests in Cairo that ousted president Hosni Mubarak.
On Monday he also announced the 34 members of his party who won seats will quit parliament.
He has joined forces with Tahir-ul-Qadri, a Barelvi cleric with a considerable support base, who also wants to see the resignation of the government.
|Significant number of women take part in march|
The protests in the capital have already gone on for five days. The prospect of the standoff continuing outside the nation's parliament could see the army playing an arbitration role.
Late on Tuesday army spokesman General Asim Bajwa tweeted an appeal for "patience, wisdom [and] sagacity from all stakeholders through larger national and public interest".
Over the last year Sharif has been weakened by damaging disputes with the powerful military establishment which removed him from power in the 1999 coup led by Pervez Musharraf.
Despite an outright parliamentary majority, the ongoing political crisis is likely to weaken him further and could make him reliant on the army for his political survival.
After entering red zone, Imran Khan said that neither police nor army will stop them to oust the prime minister. If Nawaz Sharif did not resign by tomorrow, he will storm into prime minister house. Within 15 minutes of Imran's announcement, army's statement appeared on twitter in which DG ISPR Major General said "
Soon after this release tweets of Zahid Hussain , senior journalist said "The government's authority has collapsed as the the marches entered the red zone. what next?" , " It is a soft military coup in progress. The ISPR statement makes it clear who is in charge now. there is a complete meltdown of the govt". " Sobedar major Ajab Khan now in charge of of interior ministry control room. Seems he is the the new interior minister".
Another senior journalist Talat Hussain tweeted " Nawaz Sharif is practically under siege. Here onwards his slide can be sharp". " ISPR categorises Imran, Qadri and Sharif as two 'fareeq' or 'parties'. Msg: Nawaz is no longer a prime minister".